Won't turn on, No power

'''++Joe Grober++'''  what will make this a tough repair is the fact that you already replaced all the board. did you check any of the boards before replacing them? It is entirely possible that this was/is related to bad backlight arrays etc. Post some images of all of them and the interconnect wiring with your question. Use this guide Agregar imágenes a una pregunta existente for that. Check your TV’s label and see if it has a chassis number attached to it. that will help for any revisions, service bulletins etc. Let us know. You need to be a bit specific when you say “I've tried everything “ so that we really know what you already tried. Start by using a multimeter and see if you get power to the power supply, check your fuses. Then check connector CN201to ensure you have the voltages needed to power the TV on. Let us know what you find.